But many older people are unable to get the full benefits of such training because they suffer from conditions such as arthritis that prevent them from lifting enough weight to stimulate muscle growth. And, while younger men and women continue to produce significant amounts of muscle protein for hours after a resistance exercise workout, seniors receive a much smaller post-workout benefit.
Now, though, University of Texas Medical Branch at Galveston researchers have determined that moderately and temporarily restricting the flow of blood through muscles — a practice adopted by bodybuilders who noticed that it made light weights feel heavier— can be combined with low-level resistance exercise training to produce muscle-mass increases in older men.
"We think that this may be a novel treatment for older people who need to bring their muscle mass back up," said UTMB physical therapy professor Blake Rasmussen, senior author of a paper on the investigation ("Blood flow restriction exercise stimulates mTORC1 signaling and muscle protein synthesis in older men") appearing in the May issue of the Journal of Applied Physiology. "It could also be used for patients who have had surgery and aren't capable of lifting enough weight to keep their muscles in shape, or for people who have arthritis or other conditions that make lifting heavy weights a problem."
The UTMB investigators studied changes in the thigh muscles of seven older men (average age 70) when they performed four minutes of low-resistance leg extension exercises both with and without inflatable cuffs that reduced blood flow out of the muscles. Muscle protein synthesis was measured in each of the men by monitoring changes in a chemical tracer infused into the bloodstream. In addition, a series of biopsies yielded muscle samples that were analyzed to track alterations in biochemical pathways critical to muscle growth.
"We saw that when we put the cuffs on, they responded similarly to young people doing traditional high-intensity resistance exercise," said UTMB graduate student Christopher Fry, the lead author of the paper. "The low-intensity exercise produced increases in protein synthesis, and activated two cellular pathways that stimulate protein synthesis and muscle growth in the post-exercise period."
Exactly how restricting blood flow in the muscles generated these effects remains unknown, although Rasmussen and Fry speculated that either an improved ability to activate Type II muscle fibers or a response to the sudden surge of blood into the muscles when the cuffs were released could be responsible. Whatever the mechanism, Rasmussen said, "we think it's an exciting potential new rehabilitation tool."
"You could use this following ACL knee surgery or hip fracture surgery, for example," Rasmussen said. "In the first few weeks after ACL surgery, the joint just won't allow you to lift heavy weight. So instead, you could use a really light weight with a restriction cuff, which may prevent the muscle loss that you normally see following knee surgery."
Other authors of the paper included graduate student Erin Glynn, assistant professor Micah Drummond, postdoctoral fellow Kyle Timmerman, research scientist Shaheen Dhanani and professor Elena Volpi, as well as Satoshi Fujita and Takashi Abe of the University of Tokyo. The National Institute of Arthritis and Musculoskeletal and Skin Diseases, UTMB's Institute for Translational Sciences Clinical Research Center, the UTMB Center for Rehabilitation Sciences and Sato Sports Plaza provided support for this research.
ABOUT UTMB: Established in 1891, Texas' first academic health center comprises four health sciences schools, three institutes for advanced study, a research enterprise that includes one of only two national laboratories dedicated to the safe study of infectious threats to human health, and a health system offering a full range of primary and specialized medical services throughout Galveston County and the Texas Gulf Coast region. UTMB is a component of the University of Texas System.The University of Texas Medical Branch at Galveston
Jim Kelly | EurekAlert!
Laser activated gold pyramids could deliver drugs, DNA into cells without harm
24.03.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences
What does congenital Zika syndrome look like?
24.03.2017 | University of California - San Diego
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy